Evaluating oropharyngeal carcinoma with transcervical ultrasound, CT, and MRI

To compare transcervical ultrasonography (US) to standard cross-sectional imaging for the visualization of human papillomavirus-related oropharyngeal cancer (HPV-OPC).

Patients with HPV-OPC and available standard imaging (CT and/or MRI) were identified in clinic and prospectively enrolled. US was performed to visualize the oropharynx and lymph nodes. Tumor characteristics across imaging modalities were evaluated (CT versus MRI, and US versus standard imaging (SI)).

Forty-three patients were included. The overall blinded detection rates for CT and MRI were 83% and 71%, respectively. The unblinded detection rate for US was 98%. Agreement of tumor anatomic subsite was moderate for both CT vs MRI (κ = 0.59) and US vs SI (κ = 0.47). Comparison of tumor size by CT and MRI showed statistically significant correlations in craniocaudal (CC), anteroposterior (AP), and mediolateral (ML) dimensions (Rho_CC = 0.51, p_CC = 0.038; Rho_AP = 0.81, p_AP < 0.0001; Rho_ML = 0.57, p_ML = 0.012). Tumor size estimates by US and SI showed statistically significant correlations in CC and AP, but not ML (Rho_CC = 0.60, p_CC = 0.003; Rho_AP = 0.71, p_AP < 0.0001; Rho_ML = 0.30, p_ML = 0.08). Tumor volume estimates improved correlations between US and SI (Rho = 0.66, p < 0.0001). Stratification of US patients into early and late imaging studies demonstrated an increase in correlation strength from early (Rho = 0.32, p = 0.32) to late groups (Rho = 0.77, p < 0.0001) demonstrating that ultrasound accuracy improved with experience.

Our findings suggest that transcervical ultrasonography is a sensitive and relatively accurate adjunct to standard imaging for the evaluation of oropharyngeal tumors. Its cost, portability, and potential for in-clinic and serial imaging render US an attractive modality to further develop for imaging oropharyngeal tumors.